In FIG. 1, a conventional non-centralized radio access network in form of an E-UTRAN according to 3rd Generation Partnership Project; Technical Specification Group Radio Access Network; Evolved Universal Terrestrial Radio Access (E-UTRA) and Evolved Universal Terrestrial Radio Access Network (E-UTRAN); Overall description; Stage 2 (Release 11), 3GPP LTE is shown. The evolved nodeB eNB performs all radio access network RAN related functionality. Therefore the functionality is usually executed decentralized at a local radio access point. This includes preferably the corresponding layer 1-3 functionality according to 3rd Generation Partnership Project; Technical Specification Group Radio Access Network; Evolved Universal Terrestrial Radio Access (E-UTRA); LTE physical layer; General description (Release 10) as shown in FIG. 2 where a radio resource control RRC controls and performs measurements on the physical layer. As shown in FIG. 1 the core network CN functionality is usually performed on a centralized entity or entities.
Current developments for radio access networks RAN are going to be more centralized than today's conventional radio access networks, at least partly. That means that radio access points like base stations or evolved node Bs eNBs only perform part of the radio access network protocol stack while the main part is performed centrally. A remote radio access point therefore for example performs part of the layer 1-3 of the radio access network functionality while the remaining functionality is performed at a centralized entity. This centralized entity may be a virtual base station pool executed on top of cloud-computing platforms. Examples for such an architecture include Centralized RAN, disclosed in the non-patent-literature of “C-RAN The Road Towards Green RAN,” white paper v2.5, October 2011, CMCC, or the “RAN as a Service” concept as discussed in P. Rost, C. J. Bernardos, A. De Domenico, M. Di Girolamo, M. Lalam, A. Maeder, D. Sabella, and D. Wübben, “Cloud technologies for flexible 5G radio access networks,” IEEE Communications Magazine, vol. 52, no. 5, May 2014, respectively.
Mobile radio access networks are usually subject to quality of service QoS constraints which are in particular expressed by packet delay, packet loss probability and throughput constraints. For example in 3GPP LTE, i.e. according to 3GPP Technical Specification 23.203, ‘Policy and charging control architecture (Release 8)’, www.3gpp.org, these constraints are reflected by the bearer concept introducing QCI, i.e. a quality of service QoS class of identifier. For example the general term “packet delay” comprises different parts all contributing to the delay such as air interface latency, radio access network processing latency, core network latency and latency imposed by the actual service processing used by a user terminal UE. When looking on the radio access network processing latency, this latency is imposed by encoding and decoding processes caused by forward error correction. In a conventional LTE network the encoding and decoding processes are performed by a so-called turbo-encoder/decoder or in case of a IEEE 802.16m, i.e. a WIMAX radio access network, by a so-called low density parity check LDPC code for which a message-passing decoder can be employed. This processing latency may become dominant in the radio access network if the encoding and/or decoding processing is performed on non-specialized hardware such as general purpose processes or entities like deployed in cloud-computing environments.
In US 2004/0093458, a method for controlling turbo-decoding time in a high-speed packet data communication system is described. In more detail, the decoding time of a turbo-decoder is controlled depending on the completion status of a previous transmission and a hybrid automatic repeat request HARQ status.